There is an excellent answer if you want an overview.įor reading a file you can omit the mode or pass it in explicitly: open(filename)īoth will open the file in read-only mode.

That's exactly what you need in your case.īut in case you actually want to create a file and/or write to a file you'll need a different argument here.

The second argument is the mode, it's r by default which means 'read-only'. are hidden by default when viewed in the explorer. This is especially important for Windows users because file extensions like. Note that the file extension needs to be specified. Open('/usr/local/afile') # absolute path (linux) Open('C:/users/aname/afile') # absolute path (windows) Open('adir/afile') # relative path (relative to the current working directory) For example: open('afile') # opens the file named afile in the current working directory The filename should be a string that represents the path to the file.

Buffering (I'll ignore this argument in this answer).

The most commonly used function to open a file in Python is open, it takes one mandatory argument and two optional ones in Python 2.7: I assume that you want to open a specific file and you don't deal directly with a file-handle (or a file-like-handle). To read a file into a list you need to do three things:įortunately Python makes it very easy to do these things so the shortest way to read a file into a list is: lst = list(open(filename)) Print('lines_in_textfile =', lines_in_textfile) Or: > x = open('myfile.txt').read().splitlines() We can use this Python script in the same directory of the txt above > with open('myfile.txt', encoding='utf-8') as file: This is typically how generic parsers will work. This will work nicely for any file size and you go through your file in just 1 pass. (The implementation of the Superman class is left as an exercise for you). Where you define your process function any way you want. So if you process your lines after this, it is not efficient (requires two passes rather than one).Ī better approach for the general case would be the following: with open('/your/path/file') as f: Even if it's not large, it is simply a waste of memory.Ģ) This does not allow processing of each line as you read them. The file could be very large, and you could run out of memory. In the general case, this is a very bad idea. You could simply do the following, as has been suggested: with open('/your/path/file') as f:ġ) You store all the lines in memory.

Python split keep delimiter